Historical Research

MoDOT’s Historic Preservation Section researches aspects of Missouri history for projects relating to historical archaeology, architectural history, bridges and roadways. This research can result in very detailed information on particular properties or resource types.

We present the results of our project related research in reports and at professional conferences. We write articles for inclusion in professional journals and magazines to help disseminate the information widely. We frequently give presentations on a variety of topics to local groups to help them understand what MoDOT does in the field of history and historic preservation.

We also answer inquiries from fellow MoDOT employees and from the public about the history of the highway system, bridges and ephemera related to the Department. Below is some guidance on locating historical information that MoDOT possesses. 


Historical maps are one of the best ways to track changes to the state highway system. Among the most useful maps for doing this are the Official State Highway Maps. The digitized collection of Official State Highway Maps, from the first map published in 1918 through the most-recently out-of-print map, is on the Missouri Highway Map Archive page.

County level Highway Maps were printed regularly. These maps show the state highways and local road systems. They also frequently show the locations of houses, schools, churches, cemeteries, roadside parks, and commercial development. The State Historical Society of Missouri in Columbia maintains the best collection of these maps; the Missouri State Archives also several in their collection. The MoDOT Historic Preservation Section has scans of many of these maps for use in our research. The State Historical Society of Missouri in Columbia also has an extensive collection of these maps.

Old Photographs

The State Highway Department has employed at least one professional photographer since the 1920s. This has resulted in a large collection of photographs of state highways, bridges, roadsides, scenery, State Highway Commissioners, state fair exhibits, world’s fair exhibits and Missouri subjects.

The MoDOT Negative Collection is located at the Missouri State Archives and consists of over 25,000 negatives taken between 1916 and 1965. Almost 4,000 of these images are digitized. The images are viewable at Missouri State Archives in Jefferson City.

The Missouri State Archives has an excel spreadsheet to assist researchers in finding photographs.

Researching Roads

Among the questions we are frequently asked, are questions about when road surfaces changed, when highways were paved, or when roads were widened or realigned. These types of questions can be easily answered by using Project History Maps. A Guide to Project History Maps can be found here. This document explains how to access Project History Maps, finding the area you are interested in, and understanding the codes used to describe projects.

Questions about funding of roads may also be answered by Project History Maps. This may be a starting point for those interesting in finding projects funded by the 1930s New Deal projects including the Works Progress Administration. Another good source of information about funding of state highways are the Biennial Reports of the State Highway Commission, which were published every two years. Through the 1920s and 1930s, most listed each project and its funding source. Biennial Reports can frequently be found at university libraries, the Missouri State Library, the State Historical Society of Missouri, and on-line through the Hathi Trust .

Highway Markers

The Centennial Road Law was passed in 1921. It designated numbers for state highways and directed the State Highway Commission to sign state highways in a uniform system.

In 1922 the State Highway Commission contracted with the Indestructible Sign Company of Columbus, Ohio to provide oval highway markers with “Missouri State Highways” along the edges and the highway number in the middle. At that time, a one-sided version of this marker cost $0.48 each and a two-sided version cost $0.69 each. They had an orange background with black letters and numerals. The State soon took over production of the markers.

When the U. S. Highway system was numbered in 1926 a system of federal shields was applied to the highways and the oval signs were used for Missouri highways that were not part of the U. S. highway system. The oval markers were used until 1931, when they were replaced with a Missouri-shaped shield.

Roadside Parks & Waysides

Missouri had two distinct phases of roadside park development. In the 1930s and early 1940s several roadside parks were developed in southern Missouri using rustic features. These parks often feature stone fireplaces and walls as well as north arrows and elevation markers. They were sited to take advantage of outstanding scenic views, commemorate historical events and to provide picnic facilities.

In the post-World War II years additional parks were developed. The system topped out at over 100 in 1962. These parks use a modern aesthetic with simple picnic benches and iron grills.

Local garden clubs or civic organizations sponsored Roadside Parks, many contained Blue Star Memorial markers. Locations of roadside parks can be found on state highway maps.

Additional information on Roadside Parks and early roadside beautification efforts can be found here.